I generally buy new gear when buying solid-state receivers, home theater gear. New gets you into the shiny-object realm with the latest features and compatibility in the AV realm along with Internet radio and iPods. If you don't go new then you can’t play with those latest technologies...
My recent interest in tube gear lends itself more to buying used than new. I also bought a pair of Avalon speakers used, what a bargain that was. I would say that they have really been the trigger that got me to my next level as a music listener.
In my audio path, there have been several trigger events like those speakers. When I was 14, I saved my money and bought a Heathkit pre amp kit and also an amp kit (I still have the amp in basement storage). This provided me with a formative experience of making something work in a magical way.
My Nakamichi LX7 got me started recording off-the-air reggae which I could not buy at the time (I still have boxes of cassette tapes). The first edition of the iPod reawaken my interest in music, and it served me well on countless flights (I still have that one somewhere). The Marantz AV7005 got me into multi-channel AV (sold it when I got the Emotiva XMC, which replaced an intermediate Outlaw device).
There have been more of these events, each one exposed a new aspect that precipitated more spending and Audiogon sales. A kickstarter Pono got me into the hires digital game, which was followed by a Cambridge Audio 851N network player as well as an Ayon CD-07. The AYon is so well made and sounds so good, I am anticipating a Fedexed Ayon Titan III on Monday! As I said above, the Avalon speakers led to an Audiogon purchase of a factory pimped Rogue Cronus Magnum+ ...That introduction to tubes and great speakers forced an IC re-do with very transparent cables. I am now eying my speaker cables but will wait to see what the Titan sounds like before I upgrade...
People don’t change until reality or circumstances force change. Audiophiles seem different in that regard, in that circumstances can still force change on us but we are masters at setting up those conditions such that it becomes very difficult to eventually not upgrade...